Control mechanism for ratio-changing transmissions



1933- w. T. MURDEN ET AL 2,132,752

CONTROL MECHANISM FOR RATIO CHANGING TRANSMISSIONS Filed April 29, 1935 3 Sheets-Sheet l Oct. 11, 1938. w. T. MURDEN ET AL 2,132,752

CONTROL MECHANISM FOR RATIO CHANGING TRANSMISSIONS Filed April 29, 1935 3 Sheets-Sheet 2 Oct. 11, 1938. w. T. MURDEN ET AL 2,132,752

CONTROL MECHANISM FOR RATIO CHANGING TRANSMISSIONS Filed April 29, 1955 3 Sheets-Sheet I5 Patented Oct. 11, 1938 UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR RATIO-CHANG- IN TRANSMISSIONS ware Application April29, 1935, Serial No. 18,723

4 Claims. (Cl. Id- 1905) This invention relates to control mechanism for a ratio changing transmission adapted to be used with an electrically driven motor. More particularly the control mechanism isdesigned 5. for use with a ratio changing transmission, the

parts of which are incapable of relative movement when not operating to transmit motion.

It is an object of the invention to provide a control mechanism which is adapted toauto- 10 matically shift the ratio changing transmission toward its low ratio position in the event that the electrical energy fails to operate the motor.

Another object is to provide, with such a control, manually operable means to reset the ratio changing means after such an automatic return to low, and means to effect such ratio changing as'may be desired during the operation of the device.

In the drawings, Fig. l is a vertical transverse section through a ratio changing device and the control mechanism therefor, the section being substantially on line of Fig. 2 and showing the roller in elevation.

Fig. 2 is a longitudinal vertical section through the same parts, the section being on line 22 of Fig. 1.

Fig. 3 is a horizontal section corresponding to line 33 of Fig. 1. Fig. 4 is a view similar to Fig. 3 with the parts displaced.

Fig. 5 is a diagrammatic view. Referring by reference characters to the drawings, numeral II is used'to designate a housing .35 for a ratio changing transmission having a driving race l3 which is rotatable under the influence of a motor, not shown. This motor may be an electric motor as suggested by M in Fig. 5. For the operation of this motor there is shown a main line l5, a switch fuses l9, and conductors 2|, 2|, 2|". The ratio changing'transmission also includes a driven race 23 mounted to rotate with driven shaft 25. This is a well known form of transmission wherein the tilt of the rollers, one of which is shown at 21, determines the rate of rotation of race 23 and shaft 25 relative to the rate of rotation of the input race l3. It is unnecessary to show the conventional torque loading details by which the pressure between the rollers and the races is varied with the load, since these details are not a part of this invention. Of the several rollers the one marked 21 may be considered to be the so-called master roller. Like the others it is mounted for rotation 55 in a carrier 29, the latter rotatably supported in the -arms 3| of a spider. Each carrier is operablyconnected to a sliding sleeve 33 by means of arms 35 and a pin 31, the latter engaging a lug 39 on the sleeve 33. By this means the tilting of the carrier of the master roller similarly tilts the follower roller carriers. The master roller is preferably tilted by being given an inclination about its points of race contact. This is accomplished by an inclining member 4| journaled for rotation on .the axes of rotation of the roller carrier, and'it is rotated by the rocking movement given an arm 43 by a sliding member 45, the latter having arms '4l'engaging the ball 49 on the end of arm 43. The process by which the rocking of element 4| inclines the roller by means of lugs 49, by which the roller, when so inclined, automatically assumes a new tilt and in doing so tilts the carrier by means of its pivoted members 5| need not be described as this is not, per se, a part of this invention and because it is a Well known process.

A change speedtransmission of this kind should be started with the rollers in low ratio position. When the rollers and races are not rotating it is diiiicult or impossible to shift the rollers to this A secured thereto by fastening means 53 is a box 55.

Secured to the box by fastening means 51 is a housing 59 having a covering 6| secured as at 64. Journaled in the cover 6| and in a boss 63 of the housing 59 and extending into box 55 is a spindle 65. Within the box the spindle carries a-pinion 61 meshing with rack 69 secured at H to the element referred to above. This part 45 slides on rods or rails 13 carried by the box, and, as it slides, it rocks part 4| and changes the driving ratio position of the several rollers. A coil spring 'I5issecu'red at its center to the spindle and, at its periphery, is anchored as may be convenient. It functions to rotate the spindle in a direction to shift the transmission to low ratio. There is shown a cover plate 11 and fastening means 19 to enclose the spring. A pointer 8| secured to the spindle above the cover 6| serves to indicate the position of the ratio carrying rollers. Suitable indicia may be provided on the cover if desired.

Within the housing 59 the spindle is provided with a gear 33 engaging a worm 85 on a shaft 31, the latter slidable in a bore 89 of the housing. This bore is enlarged in diameter at 9I to receive a sleeve 93 surrounding the shaft. The shaft has an elongated slot 95 into which projects the reduced end of a pin member 91 threaded into a handle 99 and extending through the sleeve. A knob IEII is secured to the end of the shaft by fastening means I03. A locking member I05 is threaded into the housing adjacent the enlarged part of the bore and enters an annular groove I91 in the sleeve, permitting the sleeve to rotate but preventing its reciprocation.

The shaft 81 has an annular. groove I99 which may be engaged by a pin HI. This pin is slidably mounted in a box H3, a spring H5 within the box tending to hold the pin at itsoutward limit of motion as will be seen in Fig. 3. A spring H1 functions to project the box with the pin upwardly and thus to lift the pin from the groove as will be seen by an inspection of Fig. 4. Within the housing is a solenoid H9 supplied by a branch circuit I2I from main conductors 2I and 2I' (see Fig. 5). This solenoid pulls an armature I23 and thus rotates a lever I25. The lever is fulcrumed at I21, engages the armature at I29 and its other end is operable to push downwardly upon the box I I3 against the resistance of spring H1. If the groove is opposite the pin III the latter enters the groove. If not, the action .of the solenoid tensions spring H5 so that it will project the pin into the groove when the plunger moves to permit it to do so.

From an examination of Fig, 5 it will be under stood that numeral H9 is the equivalent of the solenoid shown in Figs. 3 and 4; that I3I is the armature; that I33 is the equivalent of the spring H1. Numeral I35 is 'the diagrammatic equivalent oflever I25. Numeral I31 corresponds with the plunger 81. As shown in. this figure, the branch circuit includes. a switch I39 normally closed by a spring MI but which may be opened by an excessive current through the main conductor 2I such as may 'occur when the motor is overloaded, this opening being effected by a solenoid I43 operable under the influence of the excessive current in main conductor 2| to overcome spring MI and. open the switch. This provision for overload is not, however, a part of our invention.

The operation is substantially as follows: If the motor is rotating and the pin, I II is in the notch I09 as shown in Fig. 3, the driving ratio may be changed as desired by rotating the handle 99. In so rotating the handle the sleeve 93 and the shaft 81 rotate together. The shaft cannot reciprocate because it is locked from doing so by pin II I. When rotated without reciprocation, it necessarily turns the worm gear 83, shaft 65, and pinion 61. This reciprocation; of member 45 changes the driving ratio. If the current supplying the motor should fail, or if, because of excessive current in the conductor 2I resulting from an overloaded motor, switch I39 should open, the solenoid H9 releases its hold on the armature and the lever I25, the spring II1 then raises the pin I II from the recess I09. Spring 15 then rotates the spindle 65, simultaneously reciprocating shaft 81 to the position shown by Fig, 4. This rotation of the spindle 65 restores the transmission to low ratio so that when the current again becomes effective to drive the motor, the motor operates with the transmission in low ratio. The ratio at which the motor was operating may be readily restored by pushing the plunger 81 back tothe position shown in Fig. 3,

whereupon' the p-in'I'II locks the plunger from further reciprocation. It is possible to accomplish' this reciprocation of the plunger because the races and rollers are now in motion.

Figs.'3 and4 show slots 59 for fastening means 51 so that the housing may be secured in adjusted positions to the end of locating the handle and knob conveniently for the operator in whatever position the power unit may be installed. This adjustment is also convenient in the event that the plunger 81 should be operated from a remote point by a flexible cable or otherwise.

, We claim:

1. Control mechanism for a ratio changing transmission, said mechanism comprising yielding means to bias said transmission toward its low ratio position, electrically responsive means to render said yielding means inoperative, and manually operable means to vary the ratio of said transmission, together with manual resetting means mounted for reciprocation by said yielding means, said manually operable means and resetting means being coaxially arranged, and meansto permit reciprocation. of the resetting means relatively to the manually operable means but to prevent relative rotation thereof.

2. Control mechanism for a ratio changing transmission for use with an electric motor, said mechanism comprising a reciprocable ratio shifting member, a rotatable spindle, gearing between said spindle and shifting member, a manually operable-rotatable and reciprocable shaft, gearing between said spindle and shaft, yielding means operable on said spindle to move said shifting member to its low ratio position, and means responsive to the source of energy supplying said motor to lock said shaft from reciprocation and thereby render said yielding means inoperative, the manual rotation of said shaft operable to rotate said spindle and change driving ratios. V, V

3. The invention defined by claim 2, said shaft locking means including a pin radially engaging said shaft, av spring to bias said pin to shaft releasing position, and a solenoid operable to overcome said spring and project said pin into looking position.

l. The invention defined by claim 2 together with a sleeve surrounding said shaft, means to prevent relative rotation of said sleeve and shaft but; to permit reciprocation of the shaft relative to the sleeve and an operating handle on said sleeve.

. 1 7 WILLIAM T. MURDEN. T. C. DELAVAL-CROW. 

